TST: Add Python 3.7 to CI testing

[cclauss]

Add Python 3.7 to CI testing. Note that on travis-ci it must run with sudo on xenial, see travis-ci/travis-ci#9069.

[charris]

Since we are already testing with 3.7-dev, I'm not convinced the travis issue still applies. Can you try simply removing the -dev bit?

[cclauss]

Did you read through the link in the commit message? 3.7 beta != 3.7 production release.

[charris]

Looks like you can also add it to .appveyor.yml, see #11600.

[mhvk]

@cclauss - thanks for noticing those issues with old ubuntu versions! This looks good to me.

A question - probably best addressed separately - is whether we should be moving some of the other tests over to xenial as well. (There is also a possible optimization that we set in astropy but (apparently) not in numpy: ccache.)

[cclauss]

travis-ci/travis-ci#9069 is still an OPEN issue because Precise and Trusty are still Travis CI's supported Linux versions so I would avoid moving to Xenial unless necessary (as it is with Py37).

[charris]

Please keep the 3.6 testing in .appveyor.yml. I arranged things as I did because we will be dropping 3.4 for 1.16 and 2.7 for 1.17.

[cclauss]

@charris Ready for your review... Have I missed anything?

[charris]

This one should not be changed, 3.6 is widespread these days, will probably be supported for a couple of years, and so using it to build the documentation makes sense. OTOH, 3.7 is brand new and not yet included in many distros.

[cclauss]

So do we revert Circle CI to Py36?

[charris]

So do we revert Circle CI to Py36?

Hmm, to tell the truth, I don't know ;) Did you try it with only one of the two changed? It cannot hurt to stick with 3.6 for a while.

[cclauss]

CircleCI change without the Makefile change is:

• https://circleci.com/gh/numpy/numpy/2660?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-build-link

[charris]

Guess it matters, good to know.

[charris]

Thanks @cclauss .